反应详情

温度

65 °C

To a solution of 4-nitro-1H-pyrazole-3-carboxylic acid (5 g, 31.8 mmol) in dry MeOH (60 ml) was added freshly crystallized p-toluenesulphonic acid monohydrate (300 mg, 1.6 mmol). The reaction mixture was heated at 65° C. for 16 hrs. MeOH was removed in vacuo. The residue was taken up with saturated aqueous NaHCO3 solution (15 ml) and extracted with EtOAc. The combined organic layers were washed with water, and then with brine, dried (Na2SO4), filtered, and evaporated. The crude product was purified by column chromatography over silica gel using 30% EtOAc/hexane) to provide the title compound as white solid (4.85 g, 89%).

1. customMeOH was removed in vacuo
2. extractionextracted with EtOAc
3. washThe combined organic layers were washed with water
4. dry with materialwith brine, dried (Na2SO4)
5. filtrationfiltered
6. customevaporated
7. customThe crude product was purified by column chromatography over silica gel using 30% EtOAc/hexane)